Minimal invasive surgery aims to reduce tissue trauma, bleeding and to improve the healing process. Such surgery is performed through tiny incisions in the skin, often only a few millimeters, through which medical instruments are inserted. A miniature camera attached to a light tube, i.e. an endoscope, may be inserted through one of the incisions to provide the surgeon of a view of the operation. The surgeon may then explore what is wrong, remove unwanted objects or body parts or repair what is inside the body etc. An example is laparoscopic surgery, which may be performed in the abdomen. Minimal invasive surgery may be performed on a body of a human being or an animal.
In order to train surgeons or veterinarians before operating on a living being, interventions may be performed on a corpse of a dead human being or animal. It is also feasible to train surgeons or veterinarians utilizing training material, e.g. models made of rubber or plastic, as e.g. disclosed in patent document US 2005/0142525 A1 by Cotin et al. Training may also be performed by simulation in virtual reality, as e.g. disclosed in patent document U.S. Pat. No. 8,007,282 B2 disclosing a medical simulation interface apparatus.
As part of the training, it may be of interest to track the movements of the instrument utilized inside the body. In the medical simulation interface apparatus disclosed by U.S. Pat. No. 8,007,282 B2, it is, for example, possible to track movements of the instruments by means of a plurality of mechanical interfaces.
However a difference between training, being in virtual reality or with model materials, and real world minimal invasive surgery, is the hygienic demands applicable when operating on living beings. There is then often a desire to be able to sterilize or clean the objects and medical instruments. Therefore arrangements used for tracking movements of instruments in prior art training apparatuses, as in U.S. Pat. No. 8,007,282 B2, have been found to be unsuitable for use in real world minimal invasive surgery.
Although the training apparatuses become better and better, there is still a step between training and real world minimal invasive surgery.